From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Diameter and tightening of cylinder head studs for the Peregrine and Bensport engines.
| Identifier | ExFiles\Box 86\1\ scan0001 | |
| Date | 4th June 1932 | |
| 219. To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c.c. Sg.{Arthur F. Sidgreaves - MD} For. HS.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} E.4/HP.4.6.32. re Bensport Engine - Cylinder Head Studs. On the present Peregrine Engine the diameter of the cylinder head studs is .25", and this has been criticised by the shops from the point of view that they are very liable to be over tightened, and it is difficult to know when to stop screwing them up. This tendency can, of course, be somewhat corrected by using a tommy bar of the correct length and diameter, but there is the risk that this may not always be followed out in practice. Personally I think we should get used to the quarter studs from the point of view of the tightening up, but there is another point to consider before we commit ourselves too far, and that is the question of the additional load thrown on to them by supercharge. On the naturally aspirated Buzzard engine we record maximum cylinder pressures of 800lbs per square inch, and on the "R" engine supercharged one atmosphere this figure rises to 1575, practically double. The figure for this pressure for our naturally aspirated car engines, we should say, is about 500 lbs per square inch, and we may expect to double it on the Bensport at some time or other. Naturally we must chiefly rely on comparison with our other engines, and we set out as follows a table showing the stud diameters, and comparative stresses we are using on our other engines. | ||